In the past, most locations such as homes had at most one set top box (STB). A location having multiple STBs was considered rare. Today though, more locations such as households have two or more STBs sharing the same digital broadcast satellite (DBS) video service. In video-distribution systems for multiple reception locations such as multiple-dwelling units, multiple-tenant units, hospitality market (e.g., hotels), and planned communities, there is often a miniature “headend” to receive the video signal (e.g., a direct broadcast satellite (DBS) or terrestrial broadcast) and then distribute the signal throughout the premises. The DBS and/or terrestrial antennas, amplifiers, bridges, set-top boxes (STBs), and other video equipment may communicate in a limited manner.
One communication protocol that is used in video distribution systems or is provided as part of a video distribution system component is the Digital Satellite Equipment Control (DiSEqC) protocol (DiSEqC being a trademark of Eutelsat, the European Telecommunications Satellite Organization). A DiSEqC system is a communication bus particularly used between satellite receivers and satellite peripheral equipment (e.g. multi-switches, LNBs), using coaxial cable as the network media. DiSEqC can be integrated into consumer satellite installations and replace conventional analog (voltage, tone or pulse width) switching and other control wiring between devices.
DiSEqC, as defined by Eutelsat, is a single master, single or multiple slave system. The DiSEqC protocol was designed for applications where there is one bus “master” and all other DiSEqC-compatible devices in the system are considered DiSEqC “slaves”. With the DiSEqC protocol, only a DiSEqC master device may initiate communication. A DiSEqC slave will reply, if defined by the DiSEqC command it received, to the DiSEqC master, but the DiSEqC slave, however, cannot initiate communication. Thus, communications can be initiated only by the DiSEqC master device. The DiSEqC master device is typically an integrated receiver device (IRD); also known as a set-top box (STB).
A traditional DiSEqC system cannot support multiple STBs because each STB would be considered a DiSEqC “master”. Currently, because of such constraints, each STB is wired as a separate DiSEqC system to its associated LNB. DiSEqC communication between STBs is thus not possible because each STB would want to act as a DiSEqC master. (see DiSEqC Bus Functional Specification”, version 4.2, European Telecommunications Satellite Organization, Feb. 25, 1998). Applications have thus been encountered where it would be advantageous for multiple STBs within a video distribution system to function as DiSEqC “masters”.
The typical consumer now has more that one television. As such, direct broadcast satellite (DBS) systems are offered that includes multiple satellite receivers or set-top boxes, one for each television. Because such video distribution systems cannot support multiple STB master devices, the multiple STBs are each activated without regard to any other STB. This permits an STB to be moved to another location outside of the original video distribution system. In this manner non-subscribers may receive satellite television through another video distribution system. This presents a theft of service problem regarding such video distribution systems.
It is evident from the above that there is a need to address multiple STB video distribution systems.
It is thus evident from the above that there is a need to provide for multiple master devices in a direct broadcast satellite video distribution system.
It is also evident from the above that there is a need for a DiSEqC compatible video distribution system that allows for more than one DiSEqC master device.